The adverb instead means in place of or as a substitute for something else. If your best friend has a temper tantrum every time you play miniature golf, maybe next time you should go to the movies instead.
The adverb instead was originally two words, "in stead," with "stead" coming from stede, the Old English word for place. The adverb instead can also mean rather than, and in this context it's usually followed by "of." Instead of worrying about the weather for your vacation, which is beyond your control, you should worry about whether you packed everything you need.